In open-pit mining operations it is common practice to utilize very large machines. One such typical machine is a hydraulically operated digging machine or shovel that includes a huge bucket equipped with a number of metal teeth. The bucket has a leading edge on which the metal teeth are carried, and during the operation of the machine the teeth are pushed into hard earth and rock to recover the ore. The teeth are typically made of very hard steel but are replaceable because they wear down during usage.
In some such equipment a separate metal piece, called an adapter, is used to mount each tooth on the leading edge of the bucket. The adapter is also a replaceable item. In that type of equipment the adapter is attached by pins or otherwise to the leading edge of the bucket, and the tooth is attached by pins or otherwise to the adapter.
Other forms of the equipment, however, do not use a separate tooth adapter, the tooth structure then being integrally formed to include both a tooth portion and an adapter portion. The tooth structure is therefore extremely large and attached directly to the leading edge of the bucket.
A problem which has occurred from time to time is that a portion of the steel tooth structure—a steel tooth, an adapter, or some combination thereof—may become separated from the bucket to which it is normally attached, and may then be carried away with the ore in a haul truck to the ore crusher. Because of the huge size of the haul trucks a steel tooth structure weighing a ton or more can pass unnoticed into the ore crusher. The hard steel of the tooth structure cannot be easily pulverized by the crusher, with the result that the crusher itself is seriously damaged.
Such damage to the ore crusher not only requires repair of the crusher itself, but may require shutting down an entire operation, perhaps including numerous digging machines, entailing a very large financial loss before the operation can be resumed. A single shut-downs may involve a loss in excess of a million dollars.